Duo Core 2 & Windows XP HOME (S2)

Question

I just purchased an iMac 20" Duo Core 2. Being that I'm NOT an experienced Mac user, I had the CompUSA service tech install Windows for me. He told me that I couldn't install Windows XP HOME (S2) - that I had to install Windows XP Pro (S2) because of the new Duo Core 2 processor. XP Pro cost an extra $100.
Does anyone know how accurate this is? The current version of Boot Camp (1.1.1) states that XP HOME (S2) can be used.
If I had been better informed, I could have bought the 24" iMac with the money the Techs weasled me out of with their bad information and bad install of the XP system. I had to reinstall XP when I got home.
Thanks for your replies.

Answer 1

I've seen a few people stuble into this confusing area before, it is interesting to see that Microsoft isn't making things any clearer on their web page. Unfortuneatly mhunter was off base. As you can see on this page,
http://www.microsoft.com/licensing/highlights/multicore.mspx
Microsoft differentiates a processor from a core pretty clearly. At the bottom of the page it even mentions that while the per processor licensing (a server thing) doesn't apply to XP Pro, or XP Home the following applies...
"A. Microsoft Windows XP Professional and Microsoft Windows XP Home are not affected by this policy as they are licensed per installation and not per processor. Windows XP Professional can support up to two processors regardless of the number of cores on the processor. Microsoft Windows XP Home supports one processor."
A better description of this policy, and the product hardware limitations that are put in place can be found in the following Microsoft technical briefing paper.
http://download.microsoft.com/download/f/1/e/f1ecd771-cf97-4d98-9a1b-b86e3f24e08 f/multicorehyperthreadbrief.doc
In which it clearly states,
Software Do technically enforced processor limits
support multicore and hyperthreaded processors?
Windows XP Home Edition Yes
Windows XP Media Center Edition Yes
Windows XP Professional Yes
This microsoft BLOG page summarizes what I have outlined here.
http://blogs.msdn.com/oldnewthing/archive/2006/10/02/780255.aspx
The bottom line it, XP Home DOES support multiple cores on a single processor. If you have multiple processors, You'll need XP Pro regardless of how many cores they have.
More proof of this can be seen here.
http://searchwincomputing.techtarget.com/tip/0,289483,sid68_gci1189223,00.html
From this link you can see that XP Home does indeed install the Hardware Abstraction Layer (HAL) to support multple cores on a single processor (like the Intel iMacs). If you had a MacPro, XP Pro would be your only choice.
It's interesting to me that this issue is still so unclear since the PC world addressed it some time back.
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